Problem: Solve for $r$, $ \dfrac{5r - 4}{3r - 9} = 10$
Multiply both sides of the equation by $3r - 9$ $ 5r - 4 = 10(3r - 9) $ $5r - 4 = 30r - 90$ $-4 = 25r - 90$ $86 = 25r$ $25r = 86$ $r = \dfrac{86}{25}$